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Molecule Parameter List for DAG | The statistics table lists the distribution of a molecule acting either as a substrate, product, enzyme or as a molecule within the network. The text color of a molecule is highlighted by color. | Statistics | Accession and Pathway Details | |
Accession Name | Accession No. | Accession Type | Pathway Link | Ajay_Bhalla_ 2004_Feedback_ Tuning | 78 | Network | Shared_Object_Ajay_Bhalla_2004_Feedback_Tuning, PKC, PLA2, PLCbeta, Gq, MAPK, Ras, EGFR, Sos, PLC_g, CaMKII, CaM, PP1, PP2B, PKA, AC | This model is taken from Ajay SM, Bhalla US. Eur J Neurosci. 2004 Nov;20(10):2671-80. This is the feedback model from Figure 8a. |
DAG acting as a Molecule in Ajay_Bhalla_2004_Feedback_Tuning Network
DAG acting as a Product of an Enzyme in Ajay_Bhalla_2004_Feedback_Tuning Network
| Enzyme Molecule / Enzyme Activity | Accession Name | Pathway Name | Km (uM) | kcat (s^-1) | Ratio | Enzyme Type | Reagents | 1 | PLC-Ca / PLC-Ca | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PLCbeta Pathway No. : 350 | 19.8413 | 10 | 4 | explicit E-S complex | Substrate PIP2
Product DAG IP3
| | From Sternweis et al Phil Trans R Soc Lond 1992, also matched by Homma et al. k1 = 1.5e-5, now 4.2e-6 k2 = 70/sec; now 40/sec k3 = 17.5/sec; now 10/sec Note that the wording in Sternweis et al is ambiguous re the Km. | 2 | PLC-Ca-Gq / PLCb-Ca-Gq | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PLCbeta Pathway No. : 350 | 5.00003 | 48 | 4 | explicit E-S complex | Substrate PIP2
Product DAG IP3
| | From Sternweis et al, Phil Trans R Soc Lond 1992, and the values from other refs eg Homma et al JBC 263(14) pp6592 1988 match. k1 = 5e-5/sec k2 = 240/sec; now 120/sec k3 = 60/sec; now 30/sec Note that the wording in Sternweis et al is ambiguous wr. to the Km for Gq vs non-Gq states of PLC. K1 is still a bit too low. Raise to 7e-5 9 Jun 1996: k1 was 0.0002, changed to 5e-5 | 3 | Ca.PLC_g / PIP2_hydrolysis | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PLC_g Pathway No. : 356 | 97.2222 | 14 | 4 | explicit E-S complex | Substrate PIP2
Product DAG IP3
| | Mainly Homma et al JBC 263:14 1988 pp 6592, but these parms are the Ca-stimulated form. It is not clear whether the enzyme is activated by tyrosine phosphorylation at this point or not. Wahl et al JBC 267:15 10447-10456 1992 say that the Ca_stim and phosph form has 7X higher affinity for substrate than control. This is close to Wahl's figure 7, which I am using as reference. | 4 | Ca.PLC_g* / PIP2_hydrolysis | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PLC_g Pathway No. : 356 | 19.7917 | 57 | 4 | explicit E-S complex | Substrate PIP2
Product DAG IP3
| | Mainly Homma et al JBC 263:14 1988 pp 6592, but these parms are the Ca-stimulated form. It is not clear whether the enzyme is activated by tyrosine phosphorylation at this point or not. Wahl et al JBC 267:15 10447-10456 1992 say that this has 7X higher affinity for substrate than control. |
DAG acting as a Substrate in a reaction in Ajay_Bhalla_2004_Feedback_Tuning Network
Kd is calculated only for second order reactions, like nA+nB <->nC or nA<->nC+nD, where n is number and A,B,C,D are molecules, where as for first order reactions Keq is calculated.
Kd for higher order reaction are not consider. |
| Name | Accession Name | Pathway Name | Kf | Kb | Kd | tau | Reagents | 1 | PKC-act-by-DAG | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PKC Pathway No. : 348 | 0.008 (uM^-1 s^-1) | 8.6348 (s^-1) | Kd(bf) = 1079.3729(uM) | - | Substrate DAG PKC-Ca
Product PKC-Ca-DAG
| | Need est of rate. Assume it is fast Obtained from param search kf raised 10 X : see Shinomura et al PNAS 88 5149-5153 1991. kf changed from 3.865e-7 to 2.0e-7 in line with closer analysis of Shinomura data. 26 June 1996: Corrected DAG data: reduce kf 15x from 2e-7 to 1.333e-8 | 2 | PKC-n-DAG | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PKC Pathway No. : 348 | 0.0006 (uM^-1 s^-1) | 0.1 (s^-1) | Kd(bf) = 166.6658(uM) | - | Substrate DAG PKC-cytosolic
Product PKC-DAG
| | kf raised 10 X based on Shinomura et al PNAS 88 5149-5153 1991 closer analysis of Shinomura et al: kf now 1e-8 (was 1.66e-8). Further tweak. To get sufficient AA synergy, increase kf to 1.5e-8 26 June 1996: Corrected DAG levels: reduce kf by 15x from 1.5e-8 to 1e-9 | 3 | DAG-Ca-PLA2-act | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PLA2 Pathway No. : 349 | 0.003 (uM^-1 s^-1) | 4 (s^-1) | Kd(bf) = 1333.3467(uM) | - | Substrate DAG PLA2-Ca*
Product DAG-Ca-PLA2*
| | 27 June 1996 Scaled kf down by 0.015 from 3.33e-7 to 5e-9 to fit with revised DAG estimates and use of mole-fraction to calculate eff on PLA2. | 4 | Degrade-DAG | Ajay_Bhalla_ 2004_Feedback_ Tuning Accession No. : 78 | PLCbeta Pathway No. : 350 | 0.15 (s^-1) | 0 (s^-1) | Not applicable** | - | Substrate DAG
Product PC
| | These rates are the same as for degrading IP3, but I am sure that they could be improved. Lets double kf to 0.2, since the amount of DAG in the cell should be <= 1uM. Need to double it again, for the same reason. kf now 0.5 27 June 1996 kf is now 0.02 to get 50 sec time course 30 Aug 1997: Raised kf to 0.11 to accomodate PLC_gamma 27 Mar 1998: kf now 0.15 for PLC_gamma | ** This is a trasport reation between compartments of different volumes. Therefore Kd is not applicable. Please Note Kf, Kb units are in number of molecules instead of concentration
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